"We hypothesize that this is because pornographic website owners already make money from the Internet and, as a result, have a vested interest in keeping their sites malware-free  it's not good for repeat business," the company said.

Symantec didn't go into detail about what it considered to be a religious or ideological website. Overall, the company identified 403 million unique malware variants in 2011, while the number of Web attacks that were blocked on a daily basis jumped 36 percent.

On its list of most dangerous website categories, blogs/Web communications landed at No. 1 with 19.8 percent being infected. That was followed by hosting/personal hosted sites (15.6 percent), business/economy (10 percent), shopping (7.7 percent), and education/reference (6.9 percent). Porn landed at No. 10 with 2.4 percent.

Evidence suggests that scammers are getting a bit more sophisticated, too. "Badly-spelled, implausible email has been replaced by techniques such as 'clickjacking' or 'likejacking' where a user visits a website to watch a tempting video and the attackers use that click to post a comment to all the user's friends on Facebook, thereby enticing them to click on the same malicious link," Symantec said.

Chloe Albanesius has been with PCMag.com since April 2007, most recently as Executive Editor for News and Features. Prior to that, she worked for a year covering financial IT on Wall Street for Incisive Media. From 2002 to 2005, Chloe covered technology policy for The National Journal's Technology Daily in Washington, DC. She has held internships at NBC's Meet the Press, washingtonpost.com, the Tate Gallery press office in London, Roll Call, and Congressional Quarterly. She graduated with a bachelor's degree in journalism from American University...
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